Air conditioning control panel does not operate

This circuit consists of the air conditioning control and the air conditioning amplifier. When the air conditioning control is operated, signals are transmitted to the air conditioning amplifier through the lin communication system.

If the lin communication system malfunctions, the air conditioning amplifier does not operate even if the air conditioning control is operated.

1. Check wire harness (air conditioning control assembly - body ground)

1. 1
   Disconnect the air conditioning control assembly connector.
2. 2
   measure the resistance of the wire harness side connector.

Standard resistance

2. Check wire harness (air conditioning control assembly - battery)

1. 1
   Disconnect the e23 air conditioning control assembly connector.
2. 2
   Measure the voltage of the wire harness side connector.

Standard voltage

3. Check wire harness (air conditioning amplifier - air conditioning control)

1. 1
   Disconnect the e23 control connector.
2. 2
   Disconnect the e37 amplifier connector.
3. 3
   Measure the resistance of the wire harness side connectors.

Standard resistance

1. 1
   Replace air conditioning amplifier
2. 2
   Replace the air conditioning control with a new or properly functioning one.
3. 3
   Operate the air conditioning control to check that it functions properly.